Glaucoma is a group of diseases which result in a progressive loss of retinal ganglion cells, producing characteristic optic nerve head appearance with corresponding visual loss. The aetiology remains unclear until today. Previous authors had tried to associate its pathology in relation to intracranial pressure level. We review the literature on interrelation of intraocular pressure (IOP) and intracranial pressure (ICP) which gives rise to the study of translaminar pressure gradient (TLPG) in postulating its causal factor towards glaucoma. Several studies had demonstrated that ICP was reduced in patients with glaucoma, and in sequence with normal or raised IOP, leads to increased level of TLPG. The increased TLPG which acts across the lamina cribrosa may cause a posteriorly bowed lamina cribrosa, therefore leading to glaucomatous changes. This review also explores the current available methods in
measuring ICP accurately. Further studies are needed to elucidate possible disease mechanism in keeping with IOP-ICP relationship, thus confirming the findings of
previous authors.
Keywords: Glaucoma, intracranial, intraocular, pressure, pathophysiology, translaminar
Posterior Polymorphous Dystrophy (PPD) is a rare, innocuous and asymptomatic condition in which corneal endothelial cells display characteristics similar to epithelium. It is often bilateral and frequently asymmetric. We report a case of a 10-year-old girl with a family history of glaucoma who presented with right eye blurring of vision since few years. She had frequent spectacle-prescription changing due to unimproved visual acuity. Cycloplegic refraction revealed high astigmatism and moderate amblyopia over the right eye. Her best corrected vision was 6/9 for the right and left eyes. Slit-lamp examination showed a vesicular-like lesion at the periphery of corneal endothelial layers in both eyes. Endothelial cell density was much reduced on the right eye compared to the left, with more severe astigmatism. Other ocular examinations were unremarkable. Patient was instructed to patch her better left eye periodically. Although patients with Posterior Polymorphous Dystrophy (PPD) present at the age of adulthood, the age at diagnosis is highly variable. It is rare and inherited through an autosomal dominant pattern. PPD may rarely lead to astigmatism, by which was present in the patient due to the features of non-keratoconic and keratoconic cornea on the right and left eye, respectively. Endothelial cell counts were reduced more on the right eye compared to the left, which later may worsen her visual acuity thus indicating corneal transplant in the future. Patient also had a strong family history of glaucoma. Hence, screening of associated disease of corneal endothelial dystrophy in the family may be necessary.